Verified answer

Activity

1. Take two aluminium channels of different lengths.  

2. Place the lower ends of the channels on the floor and hold their upper ends at same height  

3. Now take two balls of the same size and weight and release them from the top end of the channels. They will roll down and cover the same distance.

_______________________________________

Questions

1. At the moment of releasing the balls, which energy do the balls have?

2. As the balls roll down which energy is converted into which other form of energy?

3. Why do the balls cover the same distance on rolling down?

4. What is the form of the eventual total energy of the balls?

5. Which law related to energy does the above activity demonstrate? Explain.

_______________________________________

Answers

1.  At the moment of releasing the balls, the balls have potential energy.

2. As the balls roll down, the potential energy is converted to kinetic energy.

3. Due to the same height of the channels and the same weight of the balls, the two balls will have the same potential energy when they roll down. Following the law of conservation of energy, when the balls come down of their respective channels, they will possess the same kinetic energy. Therefore the balls will possess the same velocity at the end of the channel (bottom of the channel). Due to the same velocity possessed, they'll cover equal distances on the ground. Therefore the two balls will cover the same distance after rolling down because they had possessed the same potential energy on the top of the channels.

4. Kinetic energy is the form of the eventual total energy of the balls.

5. The above activity mentioned, demonstrates the "Law of Conservation of Energy". The total mechanical energy of the balls on the top of the channels is in the form of potential energy. As the balls roll down, they are in motion. This motion represents that now these balls also possess kinetic energy. Law of Conservation of Energy states that we can't create or destroy energy. So we can say that kinetic energy came into existence because the potential energy of the ball decreases. The total mechanical energy of the balls, when reaches the bottom, is in the form of kinetic energy. This proves that the potential energy of the ball got converted into kinetic energy as it reached the bottom.

_______________________________________